The key to curing mental retardation depends on the degree of mental retardation. Mental retardation, also known as intellectual disability, generally refers to a persistent impairment of cognitive activity as well as impairment of mental activity due to organic damage to the brain or due to incomplete brain development. Mental retardation is classified into four grades: mild, moderate, severe and very severe, with different prognoses.1. Mild to moderate mental retardation: If the mental retardation is mild or moderate, most of the patients with mild mental retardation as well as some of the patients with mild mental retardation are able to achieve the state of self-care through standardized treatment. Therefore, for patients with mild to moderate mental retardation, they must not give up, and must do rehabilitation training seriously, and some of the patients have no big difference with normal people through treatment; 2. Severe and extremely severe mental retardation: for patients with severe and extremely severe mental retardation, the prognosis is often poor, and the patients can be applied with drugs that nourish the brain cells and improve the brain function, as well as cognitive-behavioral therapy, but the efficacy of the treatment may not be very obvious. However, the curative effect may not be very obvious.